Thermodynamics: Basic Topics

What is thermodynamics?

A branch of physics which deals the relationship between heat and the other forms of Energy. In particular, we read about thermal energy and how it affects to atoms or molecules (matter) in thermodynamics. Thermal energy occur due to temperature of system.

Heat

Heat is a form of energy which transferred between substance or system due to difference in temperature. It transferred from high temperature to low temperature. It cannot be created or destroyed. We can transfer it and change into other forms.

Foe a example, Steam turbine can change heat into kinetic energy and generator can change it into electrical energy. Bulb can change electrical energy into electromagnetic radiation (light) which absorb by nature and it change back into the heat. So, we can change heat into other forms but we cannot create or destroyed it. It always conserve.

Heat Transfer

we can transfer the heat with 3 different ways:

Conduction: We can transfer the heat via solid that called conduction.

Convection: We can transfer the heat via fluid that called convection.

Radiation: We can transfer the heat via photons (emission of electromagnetic energy) that called radiation.

Temperature

it is a measurement of average kinetic energy. It tells that how much heat transferred or what is amount of transferred heat. Temperature depends on the speed and numbers of the molecules in motion. If the speed of molecules in any object is higher then maximum heat transfer and if the number of molecules is high then also maximum heat transfer means that the temperature will be high.

If the temperature of the system is 0K then it means that there is no any motion of molecules and total absence of heat.

Thermal conductivity

Thermal conductivity is a rate of heat energy transfer per unit time and per unit area. It shown by k. If value of k is high then heat transfer quickly.

Foe copper and silver (Cu and Ag) the value of k is high (401 and 428). So Cu and Ag usually uses in computer chips for cooling them.

The highest value of k is for diamond in the world and that is 2,200 w/m.k.

Entropy

A measure of the disorder and randomness in a closed system is called entropy. Entropy is a waste energy means that it is a kind of energy that cannot use for any work. It always increases.